Modern vehicles can include several devices that communicate data signals with each other to control operations of the vehicles. For example, onboard devices of the vehicles can communicate to determine speeds, accelerations, braking actions, or the like, of the vehicles. Some of these vehicles, such a rail vehicles, can have systems that communicate with off-board devices. These off-board devices can provide data that is used to determine the location of the vehicle, the speed of the vehicle, speed limits of the route being traveled upon, locations where braking is required, or other information.
The varied communication used by vehicles can pose a significant security threat to operation of the vehicles. Malicious signals sent from devices to the vehicles could alter operation of the vehicles. For example, rail vehicles may receive signals that cause the rail vehicles to ignore speed limits, braking instructions, or the like. These signals can result in the vehicles operating in unsafe manners, which could result in significant injury and damage.